internal/frontend: remove use of goldmark for readme rendering

delete the code that uses goldmark and clean up the variants of the
code that use the markdown parser

For golang/go#61399

Change-Id: I03e8c303086110278dd0f3994ba97729e0cbf7c1
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/550039
Reviewed-by: Jonathan Amsterdam <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
TryBot-Bypass: Michael Matloob <[email protected]>

Author: matloob

go.mod

@@ -27,8 +27,6 @@ require (
 	github.com/jba/templatecheck v0.6.0
 	github.com/lib/pq v1.10.9
 	github.com/russross/blackfriday/v2 v2.1.0
-	github.com/yuin/goldmark v1.6.0
-	github.com/yuin/goldmark-emoji v1.0.1
 	go.opencensus.io v0.24.0
 	golang.org/x/mod v0.14.0
 	golang.org/x/net v0.19.0

go.sum

@@ -1039,9 +1039,6 @@ github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9dec
 github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 github.com/yuin/goldmark v1.6.0 h1:boZcn2GTjpsynOsC0iJHnBWa4Bi0qzfJjthwauItG68=
-github.com/yuin/goldmark v1.6.0/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
-github.com/yuin/goldmark-emoji v1.0.1 h1:ctuWEyzGBwiucEqxzwe0SOYDXPAucOrE9NQC18Wa1os=
-github.com/yuin/goldmark-emoji v1.0.1/go.mod h1:2w1E6FEWLcDQkoTE+7HU6QF1F6SLlNGjRIBbIZQFqkQ=
 github.com/yuin/gopher-lua v0.0.0-20200816102855-ee81675732da h1:NimzV1aGyq29m5ukMK0AMWEhFaL/lrEOaephfuoiARg=
 github.com/yuin/gopher-lua v0.0.0-20200816102855-ee81675732da/go.mod h1:E1AXubJBdNmFERAOucpDIxNzeGfLzg0mYh+UfMWdChA=
 github.com/yvasiyarov/go-metrics v0.0.0-20140926110328-57bccd1ccd43/go.mod h1:aX5oPXxHm3bOH+xeAttToC8pqch2ScQN/JoXYupl6xs=

internal/frontend/goldmark.go

@@ -259,7 +259,7 @@ func readmeContent(ctx context.Context, u *internal.Unit) (_ *Readme, err error)
 	if !u.IsRedistributable {
 		return &Readme{}, nil
 	}
-	return ProcessReadmeMarkdown(ctx, u)
+	return ProcessReadme(ctx, u)
 }
 
 const missingDocReplacement = `<p>Documentation is missing.</p>`